Search for narrow baryonia with negative and positive strangeness

A search for baryonia with negative and positive strangeness decaying respectively into\(\Lambda + \bar p + pions\) and\(\bar \Lambda + p + pions\) has been carried out in a neutron beam with a mean momentum of ≅40 GeV/c in an experiment performed at the Serpukhov accelerator. There is a strong indication of the existence of these baryonia. The following four charge states are observed for negative and positive strangeness: neutral, negative, positive and doubly charged. Their mean mass is 3055±25 MeV/c2 and the width Γ≦36±15 MeV/c2. The data show that the isotopic spin of the baryonia is ≧3/2. The baryonia production cross sections in the acceptable kinematic regionX F ≧0.2 andP T ≦1 GeV/c times the branching ratios of the observed decays are of the order of 1 μb per nucleon.